This invention relates to the treatment of helminth infections (helminthiasis) in animals. The term helminth refers to nematodes, roundworms, flatworms and other worms which infest the gastro-intestinal tract, lung, liver and other organs. Animals attacked by such helminths may show retarded growth or poor increase in weight because of insufficient utilization of feed given to them; moreover injuries may occur which can result in the death of the animals. Compounds such as hygromycin, phenothiazine, piperazine, and pyridyl benzimidazoles, and their derivatives have been described as useful in the treatment of this disease.
It has now been found that a group of phosphorylated thioureas which have hitherto been found useful as fungicides and biocides also possess anthelmintic activity in animals, particularly in poly-gastric animals such as sheep, cattle, goats and the like. Compounds of this type and methods for preparing them are contained in U.S. Pat. No. 3,767,734 of Alexander Mihailovski and Don R. Baker.